opencensusshim - OpenCensus metrics do not use AggregationTemporality from OpenTelemetry MetricExporter

[EddeCCC]

Greetings,

at the moment I am updating opentelemetry-opencensus-shim from 1.30.0-alpha to 1.47.0-alpha.

My application is still using OpenCensus to create metrics. However, I am using the MetricExporter from OpenTelemetry. After the update, I noticed when using a Delta AggregationTemporality for the MetricExporter, OpenCensus sums are still aggregated Cumulative. It worked prior to the update.

Previously, we build the SdkMeterProvider like this:

SdkMeterProvider meterProvider = SdkMeterProvider.builder()
                                                .setResource(resource)
                                                .registerMetricReader(OpenCensusMetrics.attachTo(metricReader))
                                                .build();

After the update, it looks like this:

SdkMeterProvider meterProvider = SdkMeterProvider.builder()
                                                .setResource(resource)
                                                .registerMetricReader(metricReader)
                                                .registerMetricProducer(OpenCensusMetricProducer.create())
                                                .build();

There has been a change, which removed OpenCensusMetrics.attachTo() and introduced the OpenCensusMetricProducer (see #5835).
However, this removes the link between the OpenTelemetry MetricReader and the OpenCensusMetricProducer. Thus, the configured AggregationTemporality of the MetricExporter can not be applied to OpenCensus metrics, as far as I understand.

Is this intended? Is there some workaround?

Thanks for any feedback.

[EddeCCC]

I created a little showcase to test this behaviour: https://github.com/EddeCCC/opencensusshim-aggregation-showcase

Just run the test.

Any feedback would be awesome!

[EddeCCC]

Nevermind, the AggregationTemporality configured in the MetricExporter has never been applied to OpenCensus metrics, only to OpenTelemetry metrics.